Emory Study Finds Depression Has Negative Impact on CABG Outcome

CHICAGO -- Symptoms of depression are far more than feelings of sadness. In fact, clinical depression can have a significant impact on how people function physically in their daily lives following coronary artery bypass surgery (CABG). It might make the difference, for example, in whether someone is able to exercise or do their own housework after bypass surgery.

That's the conclusion of a study by Emory University School of Medicine and Yale University School of Medicine researchers that is being presented at a poster session today from 3:00 PM to 5:00 PM at the American College of Cardiology's 52nd Annual Scientific Sessions in Chicago.

CABG is commonly performed to relieve symptoms and improve function in patients with heart disease. Previous research has shown that up to 20 to 25 % of patients who undergo the procedure have symptoms of depression. "Depression has also been linked in other studies to a poorer prognosis including increased mortality and adverse cardiovascular events in patients with myocardial infarction, CABG, unstable angina, and congestive heart failure," says Viola Vaccarino M.D., Ph.D., of the Emory Department of Medicine's Division of Cardiology, who headed the research team. "Our results highlight another adverse effect associated with depression. We found that depressed patients specifically had less improvement in their physical function following CABG than their non-depressed counterparts."

The researchers followed 1,045 patients (763 men and 282 women), age 30 or older, after their first CABG surgery. Patients were divided into three groups -- non-depressed, mildly depressed and definitely depressed --- based on a scoring process using the standardized Geriatric Depression Scale (GDS). Physical function, which encompasses the ability to do a range of activities from mild to vigorous (such as walking, climbing stairs and pushing heavy objects), was measured using the physical component scale (PCS), derived from SF-36 Health Survey .

At the end of six months, the researchers considered a patient's physical function improved if there was at least a five point increase in their PCS score when compared to their baseline measurement. " We found that depression was a significant independent predictor of lack of functional gains even after we adjusted for factors such as age, medical history and severity of heart disease," notes Dr. Vaccarino.

Do cardiovascular disease symptoms contribute to depression? Or does clinical depression actually increase the risk for cardiovascular disease? "Both scenarios may play a role. However, we think our findings reflect the effect of depression on worsening patients' status, rather than their health causing the depression," Dr Vaccarino answers. "This study suggests that symptoms of clinical depression should be treated aggressively in CABG and other cardiovascular disease patients."

The Emory Heart Center is comprised of all cardiology services and research at Emory University Hospital (EUH), Emory Crawford Long Hospital (ECLH) Carlyle Fraser Heart Center, the Andreas Gruentzig Cardiovascular Center of Emory University and the Emory Clinic. Ranked in the top ten of U.S. News & World Report's annual survey of the nation's best Heart Centers, the Emory Heart Center has a rich history of excellence in all areas of cardiology - including education, research and patient care. It is also internationally recognized as one of the birthplaces of modern interventional cardiology.